Compact medical pumps are highly portable, which reduces the need to limit their use to a clinical setting for many medical treatments. For example, administering a drug using a pump instead of a number of injections spaced apart in time results in a more consistent treatment, which is often more effective and therefore cost effective as well. Additionally, a compact medical pumping apparatus, potentially sized so that it can be concealed in the clothes of a patient, and is capable of pumping fluids from a remote reservoir to the patient, would also be advantageous.
Another type of compact medical pump is a breast pump. Breast pumps are well known devices for extracting milk from a breast of a user. A breast pump may be used if the baby or infant is not itself able to express milk from the breast, or if the mother is separated from the baby or infant, for example, if away from the baby at work. Portable breast pumps are particularly useful for working mothers. One complaint from users is that the breast pumps are noisy. Therefore portable breast pumps, which are quiet, discreet and efficient, are key features particularly when the user is in a semi-public setting.
Regardless of the specified use, a medical pump apparatus would benefit from a gear motor pump assembly having a compact configuration. A compact gear motor pump assembly may be useful in any number of devices, such as medical devices requiring a pumping action. Additionally, because traditional gear motor pumps tend to create a noise or knocking sound during operation, it would also be advantageous to provide a gear motor pump assembly having quiet, smooth and efficient operation. Providing a compact gear motor pump assembly using an acme thread shaft and a helical gear in all stages helps in the overall smooth, quiet and discreet operation. Accordingly, the present disclosure provides these and other advantages.